Identification of an interaction network of Arabidopsis transcription factors and MAP kinases involved in chitin signaling and pathogen defense

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Chitin, found in the fungal cell walls, is an established elicitor of plant defense responses. Our previous study, using the ATH1 Affymetrix microarrays and the quantitative-reverse transcription polymerase chain reaction, identified that 118 transcription factors (TFs) were shown to respond to the chitin treatment. To investigate their potential roles in chitin signaling and plant defense, we initiated an interaction study among these different TF proteins, as well as two chitin-activated MAP kinases (MPK3/6), using yeast two-hybrid analysis. This study revealed 69 interactions among chitin responsive TFs and MPK3/6. Among them, ERF5 was selected to illustrate the involvement of the interaction network in chitin signaling and plant defense. Surprisingly, we found that ERF5 negatively regulated both chitin signaling and plant defense against Alternaria brassicicola, and positively regulated salicylic acid signaling and plant defense against Pseudomonas syringae. Additionally, ERF5 also appeared to positively regulate ethylene signaling. Therefore, the interaction network revealed in this study may play a critical role in plant defense.